Chart that converts airfoil numbers?

[mikekosatka]

I'm trying to covert some airfoils from one system to another...
any sites or web pages to start with?
I'm using moto-calc and the airfoil choices are slim (i.e. NACA0009 is there but not 009) and I believe the NACA 009 is the same as a RG-14. I can enter the data but I hate to measure every wing I want to model in this program.
If I'm missing something obvious, please forgive my ignorance:)
Thanks in advance.
Mike ( I ain't no engineer) K.

[Ollie]

There is no such thing as an NACA three digit family of airfoils to my knowledge. The RG airfoils are not the same as any NACA airfoils. Acording to the MotoCalc web site the latest version of MotoCalc has over 800 airfoils to choose from. Its mainly a case of knowing the right nomenclature to be able to select the correct airfoil.

I don't know what you are getting at. Could you be more specific about what kind of conversion and from which system to which system?

[Sparky Paul]

The very sensible NACA airfoil designation system isn't used by all designers. Mostly you have to find what code they use. Some merely add another to a sequence without any reference to camber/thickness....

[mikekosatka]

NACA 009 is from Hobby-Lobby's discription of the airfoil on the Graupner Terry. Graupner has RG 14 mod. on the box. They have both on the build sheet/plans .
I don't read or write in German but here goes...
Tragflachenprofil = RG14 mod.
Hohenleitwerksprofil = NACA 009
:confused: :confused: :confused:
I see different plane models with different airfoils (1.e. Boeing, Clark, EH, Eppler, etc) and I assumed that they often were describing the same thing, just in different systems of nomclature, and when I saw motocalc had NACA 0009 but not NACA 009 I assumed that H-L catalogue was right and that particular airfoil , and probably others was left out..
And yes, I know what assume spells!
Being new to all this stuff, I'm just trying to get a handle on it, thus the quest for sites or web pages that might tie airfoil shapes together in a way a layman could relate to.
Mike

[Ollie]

The RG15 is the wing airfoil. The NACA009 is a typographical error of the NACA 0009 which is for the tail. I doubt if MotoCalc asks for the tail airfoil. Just put in the RG15 and forget the rest. That's the best you can do since they don't specify how they modified the RG15.

[ChrisP]

This is a great site for aerofoils :
http://www.aae.uiuc.edu/m-selig/ads/coord_database.html
You will find listed both NACA 0008, which is just a slimmer version of 0009, as well as the RG 14 ('RG' from 'Rolf Girsberger').
You can easily see that RG 14 and NACA 0009 are quite different aerofoils. NACA 0009 is a symmetrical aerofoil i.e. the chord line (the halfway line between the upper and lower surfaces) is straight and RG 14 is a cambered aerofoil i.e. the chord line is curved.
'Flat bottomed aerofoils' like Clark Y are just a variant of cambered aerofoils and are usually used for reasons of building simplicity rather than any aerodynamic advantages.